1. Field of the Preferred Embodiment(s)
This invention generally relates to a pointing device for controlling the positioning, movement and operation of an electronic device, for example, a cursor on a display screen. Specifically, the specific embodiment illustrated includes: a shaft, a substrate, resistor based strain gages, a printed circuit board and control electronics mounted on the printed circuit board.
2. Cross Reference to Related and Copending Applications
The following applications are herein incorporated by reference for supportive and related teachings:
U.S. patent application Ser. No. 08/717,517, filed Sep. 23, 1996 is a collar mounted pointing stick and has the same assignee as the present invention.
U.S. patent application Ser. No. 08/756,202, filed Nov. 25, 1996 is a pointing stick with z-axis actuation and has the same assignee as the present invention.
U.S. patent application Ser. No. 08/938,274, filed Sep. 26, 1997 is a unified bodied z-axis pointing stick and has the same assignee as the present invention.
U.S. patent application Ser. No. 08/794,703, filed Feb. 4, 1997 is a z-axis pointing stick with ESD protection and has the same assignee as the present invention.
U.S. patent application Ser. No. 09/082,700 filed May 21, 1998 is a pointing stick having an interposer connecting layer and has the same assignee as the present invention.
Regarding the example of a pointing device for controlling a cursor, manufacturers of portable laptop computers, recognizing the need for placing the cursor controlling device in a permanent and more convenient location, installed a small stubby, button-like joystick centrally around the keys of the computer keyboard, specifically at the juncture of the xe2x80x9cg,xe2x80x9d xe2x80x9chxe2x80x9d and xe2x80x9cbxe2x80x9d keys of the standard xe2x80x9cQWERTYxe2x80x9d keyboard. The joystick, also known as a pointing stick, was sensitive to lateral pressure, the amount and direction of which were sensed and input into the computer to cause movement of the cursor, and the speed and direction of cursor movement corresponded to the amount and direction of pressure on the joystick. That manufacturer may also provide two upwardly extending xe2x80x9cmousexe2x80x9d or xe2x80x9cclickxe2x80x9d buttons immediately below the space bar. The joystick is connected by a flexible cable to a computer mother board where it connects to several electronic circuit devices that amplify and condition the signal coming form the joystick. The signal from the joystick is a low level analog signal. Electronic devices on the mother board amplify the low level analog signal and convert it to a digital signal.
Despite the advantages of each type of prior art cursor control, none have been easily or economically manufactured. In particular, providing the electrical connections between the resistors and the circuitry on the computer mother board has been complicated and expensive. The flexible cable runs for a length along a keyboard before connecting with the motherboard.
Further, the electrical signal coming from the joystick is a low level analog signal. As the signal travels along the flexible cable it looses some of its amplitude and is skewed due to attenuation of the signal. During travel along the cable, the signal can be corrupted due to coupling from external electromagnetic interference. These problems of routing a low level analog signal along a cable can cause erroneous readings as to the position of the pointing stick. Therefore, there is a current unmet and heretofore long felt need for a pointing stick, which is easily connected and has improved signal integrity.
3. Description of Related Art Examples of patents related to the present invention are as follows, and each patent is herein incorporated by reference for the supporting teachings:
U.S. Pat. No. Re. 35,016, is a three-axis force measurement stylus.
U.S. Pat. No. 5,489,900, is a strain sensitive columnar transducer for a data entry keyboard contains a column upstanding from the keyboard.
U.S. Pat. No. 5,473,347, is a computer pointing device for controlling the positioning, movement and operation of a cursor on the display screen of a computer.
U.S. Pat. No. 5,407,285, is an apparatus for use in a computer keyboard for cursor control is disclosed.
U.S. Pat. No. 5,521,596, is a sensor device placed either underneath a key cap or a key on a keyboard or between two keys on a keyboard so that cursor movement may be carried out from the keyboard itself.
U.S. Pat. No. 4,876,524, is an isometric control device or the like of the type having an elastic beam and strain gauges attached to the surface of the beam characterized by at least a first group of three strain gages each having an operative axis thereof inclined with a single predetermined angle with respect to the main axis of the beam, and the strain gauges disposed at a first predetermined level along the beam.
U.S. Pat. No. 4,680,577, is a multipurpose key switch for controlling cursor movement on a CRT display and for character entry includes a key cap that moves laterally to provide cursor control and that moves vertically for character entry.
U.S. Pat. No. 5,659,334, is a force sensing pointing device.
The foregoing patents reflect the state of the art of which the applicant is aware and are tendered with the view toward discharging applicant""s acknowledged duty of candor in disclosing information that may be pertinent in the examination of this application. It is respectfully stipulated, however, that none of these patents teach or render obvious, singly or when considered in combination, applicant""s claimed invention.
It is a feature of the invention to provide a pointing device for controlling the positioning, movement and operation of an electronic device, for example, a cursor on a display screen. Specifically, there is a shaft, a substrate or printed circuit board having apertures, resistor based strain gages, and control electronics mounted on the printed circuit board. The printed circuit board is mounted to a keyboard base.
It is a feature of the invention to provide a device for generating conditioned electrical signals in response to forces applied to the device. The device includes a shaft having a first and second end. A substrate has the first end of the shaft attached. Several strain sensitive resistors are mounted on the substrate around the shaft for generating an electrical signal representative of a magnitude and direction of force applied to the shaft by a user. Several apertures are in the substrate, each aperture is located between a pair of strain sensitive resistors. A signal conditioning means is mounted to the substrate, and electrically connected to the resistors for conditioning the electrical signal. The signal conditioning means operates to receive the electrical signal as an input and provides a conditioned signal as an output.
It is a further feature of the invention to provide a device for generating conditioned electrical signals in response to forces applied thereon, including an actuator, having strain sensitive resistors mounted thereon for generating an electrical signal representative of force applied to the actuator. The resistors each separated by an aperture. A printed circuit board includes the actuator and has signal conditioning means mounted to the printed circuit board and electrically connected to the resistors for receiving the electrical signal, conditioning the electrical signal and outputting the conditioned signal.
It is a further feature of the invention to provide a device for generating electrical signals in response to forces applied thereon by an operator, the device operable to be connected to an external circuit, including a shaft, having a first and second end. A substrate has the first end of the shaft attached. Several strain sensitive resistors are mounted on the substrate. The resistors are disposed radially around the shaft. The strain sensitive resistors are operable to generate an electrical signal representative of a magnitude and direction of force applied to the shaft by a user. Each resistor is separated by an aperture in the substrate. A mounting bracket contains the printed circuit board and is adapted to mounting to a keyboard base.
It is a further feature of the invention to provide a cavity disposed on a second substrate surface and the resistors are disposed on a first substrate surface such that each resistor is partially disposed above the cavity.
It is a further feature of the invention to provide an electronic control device for allowing a user to control the movement or operation of a responsive electronic system including a substrate. A resistor means is mounted to the substrate to generating an analog signal representative of a direction of mechanical force applied thereon by the user. A signal conditioning means is mounted to the substrate, for receiving the analog signal from the resistor means as an input and generate a digital signal as an output. The resistor means includes either a shaft attached to the substrate and several strain sensitive resistors mounted on the substrate, each resistor separated by an aperture, the resistors and the apertures are disposed radially around the shaft or the resistor means includes a cavity disposed on a side of the substrate with a shaft extending through the cavity and attached to the substrate and strain sensitive resistors mounted to another side of the substrate, each resistor being disposed around the shaft and partially over the cavity.
The invention resides not in any one of these features per se, but rather in the particular combination of all of them herein disclosed and claimed and it is distinguished from the prior art in this combination of all of its structures for the functions specified.
There has thus been outlined, rather broadly, the more important features of the invention so that the detailed description thereof that follows may be better understood, and so that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the appended claims. Those skilled in the art will appreciate that the preferred embodiment may readily be used as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims are regarded as including such equivalent constructions since they do not depart from the spirit and scope of the present invention.